Convert drivers currently using the qparams APIs, to instead
use the virURIPtr query parameters directly.

* src/esx/esx_util.c, src/hyperv/hyperv_util.c,
  src/remote/remote_driver.c, src/xenapi/xenapi_utils.c: Remove
  use of qparams
* src/util/qparams.h, src/util/qparams.c: Delete
* src/Makefile.am, src/libvirt_private.syms: Remove qparams
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>